Process for the direct production of pure oxid of tin.



J. I'EIIWELP. PROCESS FOR THE DIRECT PRODUCTION OF PURE OXID OF TIN APPLICATION FILED SEPT. 3, I914.-

Patented Aug. 21, 1917.

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JOHANN TERWELP, OFNEUSS, GERMANY.

: PROCESS FOR THE DIRECT PRODUCTION OF PURE OXID' F TIN.

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To all whom it may concern:

Be it known that I, JOHANN TERWELP,

chemist, a subject of the German Emperor,

and residing at Neuss, Rhine, Germany, a have invented certain new and useful Processes for the Direct Production of Pure 'Oxid of Tin, of which the following is a specification. The object of the present invention relates to to the production of pure oxid of tin, im-

mediately fit for the production of enamel from. tin-bearing materials of any kind. Preferably the oxid of tin, precipitated from the sodium stannate solutions in connection 315 With the freeing of white metal from tin (which oxid of tin has a mean percentage of from about 90 to 95% SnO or the tin paste, obtained in the dyeing of silks which paste has a percentage of from about 85% to 95% 8110,) can be used as startmg materials. a 1 The process consists in heating first the tin bearing material to approximately the reduction-temperature of the oxid oitin. The temperature may, however, also be higher but not so high, that the tin-bearing material comes to a melt; While retaining the temperature of heating and in presence of an oxidizing atmosphere, a reduc ng agent is gradually supplied-to the material, heated in this way. To this efiect gaseous and finely distributed liquid reducing agents, such as e. g. lighting eras or oil, or else solid reducing agents, sucli as finely powdered carbon 01' its equivalents are used. The latter reducing'agents are conveniently fed by means of an atomizing nozzle or With the assistance of suchdevices, as are made useof for the combustion of coal dust in connection with coal dust-furnaces. The reducing agent is gradually fed on the heated material only until all the tin has-been converted into oxid of tin. In this manner an exceedingly pure and light oxid of tin is obtained in finely distributed condition.

For carrying out the present process nothing is required but a device for heating the material to be treated, and a device for feeding the reducing agent and the oxidizing air or the like and finally a device for gathering the oxid of tin produced.

A practical form of embodiment of a device by means whereof the present process can be carried into effect is exemplified on 55 the accompanying drawing, wherein Figure 1 shows a fiame-furnace closed on top, in

solid reducing agents Specification of Letters Patent. I Pgitemibqgfi Aug 21, 1191*}. Application filed September 3,1914. Serial N 0. 60,063.

longitudinal section; Fig. 2is a'section on the line AB of Fig. 1; Fig. 3 represents a section through the line CD"oi Fig. 1.

The flame-furnace a has a hearth .b, on which the tin-bearing material to be dealt With is charged through the opening a. As soon as thematerial is placed on the hearth and the furnace is, started, such opening is hermetically closed by a plate i. The tinbearingmaterial in the furnace is heated to about 1000to 1100 C. by means of large Bunsen burners 6'. Now, while retaining the temperature, the reducing agent, in presence in of an oxidizing atmosphere, is allowed grad- 7o ua lly to act on the surface of thelglowingi material, heated in this manner. When ape plying lighting gas as reducing-agent and air as an oxidizing-agent, the Bunsen-burn ers e are used to supply a mixture of lighting gas and air, rarefied by air, which-mixture can be supplied to the burners by'means of any suitable device. During this phase of the process it will be well to stop some of the Bunsen burners e with a view of avoiding an increase in temperature during the production of .oxid of tin. When liquid or are used, theyare fed in a similar manner, by blowing the reducing agent infinely distributed form together 85 with an air current on the material to be treated. The oxid of tin, obtained in formpf vaporsin presence of an oxidizing atmosphere during the action of the reducing agent, e'stapes from the openingf into a conduit 9, which conveniently slightly ascends and is connected with the furnace. In front of the opening it of this conduit a chimney-like structure 2', open at its base and allowing inspection of the conduit, is placed. From the upper end thereof a pipe leads toward the settling chambers and collectors, Wherein the ready'product is gathered.

Ewample.

- heated material.

percentage of approximately v this being particularly fit for rial a mixture of reducing material and air in an oxidizing atmosphere.

is obtained, enameling purposes.

from 1000 to 1200 mm., is forced into the furnace chamber above the surface of the Under the temperature maintained in the furnace and in presence of the oxidizing air, one portion of the oxid after the other is reduced on the surface of the tin-bearing material, and oxidized again in 8mm nasccndi, the product formed escaping as oxid. All that is necessary is to regulate during the process the addition of the reducing agent so that all the tin that is formed is fully oxidized. In this manner a very voluminous, white product having a $970 of SnO What I claim is 1.-. The process of directly producing pure oxid of tin from tin bearing materials, which comprises heating the material to at least the reduction temperature of tin oxicl Without producing a melt, in the presence of a reducing agent, in an oxidizing atmosphere,

whereby the tin-vapor is immediately ox dized and leaves the charge as oxid fumes.

2. The process of directly producing pure tin oxid from tin bearing materials, which comprises heating the material Without admixture of reducing agent to or above the nea /Mo reduction temperature of tin oxid, and directing onto the surface of the charge a reducing agent in an oxidizing atmosphere.

3. The process of directly producing pure oxid of tin from tin bearing materials, which comprises heating the material to at least the reduction temperature of the material without a reducing agent and supplying a gaseous reducing agent to the material in the presence of air tin Vapor resulting from the reducing action. 4L. The process of directly producing pure oxid of tin from tin bearing materials, which comprises heating the materials suiliciently to reduce them, and supplying to the mate- 5. The process of directly producing pure cxid of tin from tin bearing materials, which comprises heating the materials sufiiciently to reduce them, and supplying to the surface of the material a mixture of reducing material and air in an oxidizing atmosphere.

In testimony whereof, I afiix my signature in the presence of two witnesses.

' JOHANN TERYVELP. [n s] Witnesses:

HELEN Nnrsn, ALBERT Nnrnn.

sufficient to oxidize the i 

